Martino Ferrari
d9909f2115
cover_buckets chose one level per pass, so an odd first whole bucket (half of all measurement ranges) never reached a level above 0 and folded every remaining bucket at level 0 -- 15624 entries for a 1e6-sample pyramid. Pick the largest aligned, in-range, materialised level at each cursor instead; the new cost test counts folded entries through a PLOT_PYRAMID_COUNT_COVERS-only hook (absent from normal builds) and fails on the old body. Ring slots are now relaxed std::atomic: overwrite-on-full means the producer reuses the slot of a snapshot's oldest sample while the consumer reads it, which was a data race, not just a stale value. copy_from loads explicitly instead of std::copy; push stays lock-free. A new producer/consumer case is the one TSan flags without this. Also extends the wrapped-window test with x0/bounds/pyramid/sum/sumsq/gather checks, and corrects the StreamSeries threading note to the sample-count bound.